Affiliation: ICRAR/Curtin

Contribution: Invited

Title: The Earliest Radio Sources

Abstract: Despite their low-energy, radio-photons trace extremely energetic processes in galaxies. High redshift radio galaxies serve as crucial probes of the early Universe, providing unique insights into cosmic evolution. These objects provide a window into the co-evolution of galaxies and their central supermassive black holes, while allowing us to probe the intergalactic medium at early cosmic times. Understanding AGN feedback mechanisms in these epochs is critical to unraveling how these processes shaped galaxy evolution. High redshift radio galaxies are often associated with proto-cluster environments and provide information about large-scale structure formation. Studying how their radio jets interact with the dense environments of the early Universe improves our knowledge of jet physics under extreme conditions. At lower luminosities, star-forming galaxies produce copious amounts of radio emission from synchrotron and free-free processes. Importantly, radio emission is not obscured by dust so we can accurately measure the radio luminosities of SFGs. However, the spectra of radio sources is now known to be more complex than a simple power-law with the star formation history and perhaps geometry affecting the radio spectra. These challenges can be overcome with further analysis of local analogues which will allow deep surveys with the Square Kilometre Array to provide a unique constraint on the star-formation history of the Universe. In this talk I will review high-redshift studies of both AGN and SFGs.

This contribution can be found here (pdf).